1. Field of the Invention
The invention relates to a pipeline for the transport of a pressurized flowable medium, consisting of a metal tube corrugated transversely to its longitudinal direction and of a hose which is arranged in the same and consists of plastic and which, in the position of use, bears against the inwardly pointing wave troughs of the metal tube, in which a multiplicity of holes separated from one another are formed in the wall of the hose over its entire axial length, and also to a method for producing the pipeline (DE 103 55 475 B3).
2. Description of Related Art
Pipelines of this type are used for the transport of liquids and gases. They are easily bendable on account of the corrugated metal tube and are therefore simple to lay in place. In order to avoid a pressure loss, caused by the corrugation of the metal tube, of the medium to be transported and also flow noises and vibrations of the metal tube which may be manifested in a disturbing manner in its surroundings, a smooth hose made from plastic, which is also designated as a “liner”, is mounted in the metal tube.
In the pipeline according to DE 102 41 504 A1, a pressure-resistant hose made from plastic is used, which is drawn into a prefabricated corrugated metal pipe. The pipeline is then heated to the softening temperature of the plastic used for the hose. The hose is subsequently acted upon with pressure, so that it comes to bear against the wave troughs of the metal tube and penetrates at least partially into the corrugation of the latter. When the pipeline is in operation, the pressurized medium to be transported may diffuse outwards through the wall of the hose. This leads gradually to a pressure build-up in the space between the metal tube and hose, with the result that the hose is subjected to high mechanical load. When the hose is relieved without medium to be transported, it therefore collapses on itself on account of the increased pressure acting from outside. The pipeline then has to be repaired again at high outlay or it is even no longer usable.
The known pipeline for carrying fluids according to DE 103 55 475 B3 mentioned above consists of a metallic hose which is corrugated transversely to its longitudinal direction and in which a perforated inner hose is arranged. The inner hose is mechanically connected at the ends of the pipeline to the metallic hose by means of a cold finger or adapter.